1. Field of the Invention
This invention relates generally to cooling system of chamber with removable liner, and particularly relates to cooling system which directly cools liner by gas.
2. Description of the Prior Art
Numerous semiconductor fabricating processes are performed in chamber and whole space inside chamber is affected by execution of semiconductor fabricating processes. Thus, although semiconductor fabricating processes focus on wafer(s), which is located on bottom plate of reactor, and fabrication on wafer usually are controlled by top plate, which is opposite to bottom plate, wall of chamber can not totally avoid disadvantages such as pollution and damage, especially chamber is used to execute etching process. Therefore, a direct result is that chamber, at least wall, requires frequent clean, even lifetime of chamber, at least wall, is shortened by unavoidable damages.
In response to this problem, as the cross-section illustration shown in FIG. 1A, a popular solution is to add removable liner 14 on one face, which facing wafer 12, of wall 13 to let these processes only affect bottom plate 10, top plate 11, and liner 14 but do not induce pollution and damage on wall 13. Because liner 14 is removable, it is possible to clean or substitute used liner 14 and then both lifetime and quality of wall 13 is improved. As usual, owing to liner 14 only is used to protect wall 13, devices for controlling parameters such as temperature and electric filed still are located in wall 13, to let structure of liner 14 is simplified and cost is reduced. Moreover, liner 14 usually is hanged on or locked in wall 13. Obviously, if liner 14 and wall 13 is totally stuck, as FIG. 1A shows, heat only could be propagated by conduction; and if liner and wall is not totally stuck, heat could be propagated by both conduction and radiation.
Indisputable, because both liner 14 and wall 13 would interact with any semiconductor fabricating process which is executed in chamber, it is necessary to precisely control temperature of both wall 13 and liner 14. Especially, while chamber could be heated by microwave or coil, how to control, or cool, temperature of wall 13 and liner 14 would be an indispensable part for controlling temperature inside chamber. As the cross-sectional illustration FIG. 1C shows and as top-view illustration FIG. 1D, conventional technologies usually use chill 14 to control temperature, where chiller 14 is located in wall 13 and surround wafer 12. Moreover, chiller 15 could control temperature of liner 14 which is directly affected by semiconductor fabricating process, and chiller 14 usually use liquid to carry heat away.
However, following disadvantages almost are unavoidable. First, only conduction and radiation are available between wall 13 and liner 14, but also efficiency of radiation is not good while chamber is in vacuum during execution of semiconductor fabricating processes and efficiency of conduction is limited by both shape and material of connection between liner 14 and wall 13, and then efficiency of heat propagation between liner 14 and wall 13 is not good. Next, because chiller 13 does not directly touch with liner 14 but is located inside wall 13, it is necessary to change temperature of liner 14 by changing temperature of wall 13, and then it is hard to precisely control temperature of liner 14. Further, because temperature variation of liquid which is used by chiller 15 requires a long time to achieve, it is hard to let chiller response to temperature variation in liner 14 in time, and then it is hard to modulate temperature of liner 14 in time.
In short, application of liner really could reduce maintenance cost and prolong lifetime of liner, but conventional technologies are hardly to precisely control temperature of liner. Therefore, how to precisely control temperature of liner becomes an important topic about liner application.
One main object of this invention is to present a cooling system for directly adjusting temperature of liner.
Another main object of this invention is to present a chamber with function of gas cooling, and then conventional disadvantages induced by liquid cooling could be overcame.
Still one main object of this invention is to present a technology for effectively and elastically controlling temperature of liner of chamber.
One preferred embodiment of this present invention is a cooling system of chamber with a removable liner, at least includes gas temperature adjusting assembly, gas supplying assembly, and gas controlling assembly. Gas temperature adjusting assembly is located between removable liner and a wall of said chamber. Gas supplying assembly is connected with gas temperature adjusting assembly and could be used to supply a gas which is required by gas temperature adjusting assembly. Gas controlling assembly is connected with gas supplying assembly and controls both flow rate and flow account of gas.
Another preferred embodiment is a chamber with gas cooling function, at least includes a bottom plate, a top plate, a wall, a liner, a gas pipeline, and a sealing device. Bottom plate is located under a wafer and top plate is located over this wafer, wall connects bottom plate with top plate and surrounds wafer. Liner is located between wall and wafer, liner touches with wall and is removable, however, liner is not totally stuck to well and a sealed space is located between liner and wall. Gas pipeline is connected with sealed spaced and could provide a gas to sealed space. Sealing device not only is located between liner and wall but also is located around sealed space, sealed space is surrounded by wall, liner, and sealing device but only is conducted with gas pipeline.